# #region mapping_service [C:5] [TYPE Module] [SEMANTICS mapping, database, superset, fuzzy, suggestion]
#
# @BRIEF Orchestrates database fetching and fuzzy matching suggestions.
# @LAYER Service
# @PRE  source/target environment identifiers are provided by caller.
# @POST  Exposes stateless mapping suggestion orchestration over configured environments.
# @SIDE_EFFECT  Performs remote metadata reads through Superset API clients.
# @DATA_CONTRACT  Input[source_env_id: str, target_env_id: str] -> Output[List[Dict]]
# @RELATION DEPENDS_ON -> SupersetClient
# @RELATION DEPENDS_ON -> suggest_mappings
#
# @INVARIANT  Suggestions are based on database names.


from ..core.logger import belief_scope
from ..core.superset_client import SupersetClient
from ..core.utils.matching import suggest_mappings


# #region MappingService [C:3] [TYPE Class]
# @BRIEF Service for handling database mapping logic.
# @PRE  config_manager exposes get_environments() with environment objects containing id.
# @POST  Provides client resolution and mapping suggestion methods.
# @SIDE_EFFECT  Instantiates Superset clients and performs upstream metadata reads.
# @DATA_CONTRACT  Input[config_manager] -> Output[List[Dict]]
# @RELATION DEPENDS_ON -> SupersetClient
# @RELATION DEPENDS_ON -> suggest_mappings
class MappingService:
    # region init [TYPE Function]
    # @PURPOSE: Initializes the mapping service with a config manager.
    # @PRE  config_manager is provided.
    # @PARAM  config_manager (ConfigManager) - The configuration manager.
    # @POST  Service is initialized.
    # @RELATION DEPENDS_ON -> MappingService
    def __init__(self, config_manager):
        with belief_scope("MappingService.__init__"):
            self.config_manager = config_manager

    # endregion init

    # region _get_client [TYPE Function]
    # @PURPOSE: Helper to get an initialized SupersetClient for an environment.
    # @PARAM  env_id (str) - The ID of the environment.
    # @PRE  environment must exist in config.
    # @POST  Returns an initialized SupersetClient.
    # @RETURN  SupersetClient - Initialized client.
    # @RELATION CALLS -> SupersetClient
    def _get_client(self, env_id: str) -> SupersetClient:
        with belief_scope("MappingService._get_client", f"env_id={env_id}"):
            envs = self.config_manager.get_environments()
            env = next((e for e in envs if e.id == env_id), None)
            if not env:
                raise ValueError(f"Environment {env_id} not found")

            return SupersetClient(env)

    # endregion _get_client

    # region get_suggestions [TYPE Function]
    # @PURPOSE: Fetches databases from both environments and returns fuzzy matching suggestions.
    # @PARAM    source_env_id (str) - Source environment ID.
    # @PARAM    target_env_id (str) - Target environment ID.
    # @PRE  Both environments must be accessible.
    # @POST  Returns fuzzy-matched database suggestions.
    # @RETURN   List[Dict] - Suggested mappings.
    # @RELATION CALLS -> _get_client
    # @RELATION CALLS -> suggest_mappings
    async def get_suggestions(
        self, source_env_id: str, target_env_id: str
    ) -> list[dict]:
        with belief_scope(
            "MappingService.get_suggestions",
            f"source={source_env_id}, target={target_env_id}",
        ):
            """
            Get suggested mappings between two environments.
            """
            source_client = self._get_client(source_env_id)
            target_client = self._get_client(target_env_id)

            source_dbs = source_client.get_databases_summary()
            target_dbs = target_client.get_databases_summary()

            return suggest_mappings(source_dbs, target_dbs)

    # endregion get_suggestions


# #endregion MappingService

# #endregion mapping_service